How to change component selection type in edit mode in Blender 2.8 alpha?
First of, Blender 2.8 is in development. It's an unfinished alpha product constantly changing hour after hour. So if you're not prepared to constantly change with it, you should wait for the 2.80 release.



For now, the default keymap is one of the things currently being worked on. You can follow the advancement  on the tracker here. There is also a list of shortcut being made here.

The previous component menu seems to be gone for now. Though you can use 123 to switch between each of them.